Jacob Johann Graf[1] von Sievers (Russian: Я́ков Ефи́мович Си́верс; 30 August 1731 – 23 July 1808) was a Baltic German statesman of the Russian Empire from the Sievers family.

After serving the Russian army during the Seven Years' War as quartermaster general, he was appointed governor of Novgorod in 1764 by Catherine II.

He introduced the cultivation of potatoes to Russia, regulated the postal services, and was instrumental in the abolition of torture in 1767.

Based on Sievers' initiative, the provincial government reform was instituted; he was himself appointed general governor of Novgorod, Tver and Pskov.

Emperor Paul I of Russia appointed him senator in 1796; in 1797 he became head of the new department for water communications.